2
Maintenance schedule
(continued)
7
3. Fill with fresh water until the water begins to pour out
of the drain.
4. Replace the cap. Press the cap onto the trap until the
cap makes contact with the drain.
5. Replace the retaining screw.
WARNING
The condensate trap (FIG. 2-1) must
be filled with water during all times
of boiler operation to avoid flue gas
emission from the condensate drain line.
Failure to fill the trap could result in
severe personal injury or death.
PVC TEE ASSEMBLY
(FACTORY SUPPLIED)
TO FLOOR
DRAIN
2” PVC CAP WITH
BLOCKED DRAIN SWITCH
RETAINING
SCREW
CONDENSATE FROM
HEAT EXCHANGER
Figure 2-1 Condensate Trap
Condensate disposal
1. This boiler is a high efficiency appliance that produces
condensate.
2. The side of the boiler has a 1/2 inch PVC union for
connection of a 1/2 inch PVC pipe (FIG. 2-2).
3. Slope condensate tubing down and away from the
boiler into a drain or condensate neutralizing filter.
Condensate from the Knight XL will be slightly acidic
(typically with a pH from 3 to 5). Install a neutralizing
filter if required by local codes. Call your qualified
service technician to inspect the boiler and system.
A Neutralizer Kit is available from the factory (Kit 3087
for Models 400 - 501 and Kit 30002 for Models 601 -
801). Call your qualified service technician to install.
4. Install the 1/2 inch PVC tee assembly (shipped with the
unit) as shown in FIG. 2-2. Call your qualified service
technician to inspect the boiler and system.
5. Leave the top of the 1/2 inch tee OPEN. This is needed
as a vacuum break.
6. Do not expose condensate line to freezing temperatures.
7. Use only plastic tubing or piping as a condensate drain
line (FIG. 2-2).
Use materials approved by the authority
having jurisdiction. In the absence of
other authority, PVC and CPVC pipe
must comply with ASTM D1785 or D2845.
Cement and primer must comply with
ASME D2564 or F493. For Canada use
CSA or ULC certified PVC or CPVC pipe,
fittings, and cement.
8. A condensate removal pump is required if the boiler is
below the drain. When installing a condensate pump,
select one approved for use with condensing boilers
and furnaces. The pump should have an overflow
switch to prevent property damage from condensate
spillage. Call your qualified service technician to inspect
the boiler and system.
NOTICE
NOTICE
To allow for proper drainage on large
horizontal runs, a second line vent may
be required and tubing size may need to
increase to 1 inch.
The condensate line must remain
unobstructed, allowing free flow of
condensate. If condensate is allowed to
freeze in the line or if the line is obstructed
in any other manner, condensate can exit
from the boiler tee, resulting in potential
water damage to property. Call your
qualified service technician to inspect
the boiler and system.
1/2" PVC UNION
(FACTORY SUPPLIED)
NEUTRALIZER KIT
FLOOR DRAIN OR
DRAIN PAN
1/2" PVC TEE ASSEMBLY
(FACTORY SUPPLIED)
Figure 2-2 Condensate Disposal
User’s Information Manual
